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Valuation of Corn Rootworm Control Tactics Under Varying Levels of Pressure

Predicting the extent of corn rootworm (CRW) feeding is difficult and is dependent on numerous environmental and biological factors that are beyond a grower's control.

Yield potential can be decreased and the risk of root lodging increased by CRW larval feeding.

Favorable practices for CRW include continuous corn, late-planted fields, and use of late-maturing corn products.

Importance of Corn Rootworm Larvae Control

Historical estimates suggest western corn rootworm (WCRW) and northern corn rootworm (NCRW) are responsible for nearly 1 billion dollars annually in crop losses and control costs.1 Larval feeding can decrease yield potential and increase the risk of root lodging (Figure 1). Although the average yield advantage is 20 bu/acre, data shows there can be an even greater impact of up to 80 bu/acre yield loss due to corn rootworm (CRW).2 Predicting the extent of CRW damage is very difficult, but the potential for damaging populations is more probable under certain circumstances.

Figure 1. Corn rootworm larvae.

Practices that Can Increase Corn Rootworm Pressure

In all areas of the Corn Belt, production practices that favor growth in CRW populations include, continuous corn rotations, late-planted corn fields, and/or the planting of late-maturing corn products for the area. For example, full season products used by many silage growers are often prime targets for escalating CRW beetle populations because they pollinate when other desirable adult CRW food sources have deteriorated.

Management Options

Crop rotation has been and continues to be a recommended method to effectively control CRW larvae. However, crop rotation is no longer as effective in specific areas of the Corn Belt due to NCRW extended diapause populations and the WCRW soybean variant.

Consider using soil-applied insecticides (SAI) labeled for control of CRW larvae with non-B.t. or single MOA B.t. seed products. Planting single MOA seed products such as Genuity® VT Triple PRO® or Genuity® VT Triple PRO® RIB Complete® Corn Blend products is not recommended when less than satisfactory control of CRW was achieved with the technology in the previous growing season.

Research

In efforts to define the value provided by B.t. traits and SAI's, Monsanto Technology Development Representatives conducted CRW control studies from 2010 to 2013 in twelve states to evaluate the CRW protection efficacy of Genuity® SmartStax® RIB Complete® Corn Blend products compared to similar products without B.t. CRW protection.

All products were adapted to the testing area and had their respective seed treatments. Nodal injury scores (NIS) and yield data were collected from the studies.

Results and Discussion

In Moderate- to High-Pressure Situations2 - Genuity SmartStax RIB Complete Corn Blend products provided an average advantage of 20 bu/acre over non-CRW B.t. protected corn products (Figure 2). When an SAI was used with non-CRW B.t. protected products, there was a 10 bu/acre average advantage for Genuity SmartStax RIB Complete Corn Blend products (Figure 2). Genuity SmartStax RIB Complete Corn Blend products had an NIS score of 0.29 compared to scores of 0.58 and 1.46 for non-CRW B.t. protected products with and without an SAI respectively (Figure 3). An SAI would add about $16/acre to the cost of production and should be considered when selecting seed products.

Figure 2. Expected long-term average yield.

Figure 3. Expected long-term nodal injury score.

In Low-Pressure Situations2 - Genuity SmartStax RIB Complete Corn Blend products provided an 8 bu/acre average advantage over non-CRW B.t. products that did not have an SAI.4 If farmers determine they have a low risk of damage from a CRW infestation, and decide to plant a non-CRW B.t. product without an SAI, an average 8 bu/acre in yield potential could be lost. The use of an SAI with non-CRW B.t. products may provide adequate levels of CRW control in instances of low pressure. However, due to the difficulty of predicting damage levels, growers run an exceptional risk of underestimating damage potential; thereby, incurring a substantial loss in yield. In the short-term, growers may realize modest cost savings. However, the use of non-CRW B.t. products alone or with an SAI will likely cost growers more in the long-term.

Additional Considerations

Regardless of high or low CRW pressure, Genuity SmartStax RIB Complete Corn Blend products can provide farmers a better opportunity to maintain and increase profitability. Along with the $16/acre cost for an SAI, consideration should be given to:

Soil-applied insecticides are relatively insoluble and protection is limited to a relatively small portion of the root zone.

Genuity SmartStax RIB Complete Corn Blend products offer earworm B.t. protection. Lost yield attributable to earworm feeding can be as high as 7%.3

Genuity SmatStax RIB Complete Corn Blend products are treated with Acceleron® Seed Applied Solutions plus Poncho®/VOTiVO® seed treatment that includes a 500 rate of clothianadin, which has shown an average increased yield potential of 3.7 bu/acre over other basic seed treatments.4

Farmers, through market research, have placed a value of $5/acre on refuge in the bag products.5

Genuity Rootworm Management App

iPad® device users can download an app that allows farmers to complete assessments in each field to determine the potential risk of corn rootworm damage. The tool follows proven pest management recommendations for scouting, crop rotation, utilizing dual MOA when planting, and suggesting specific insecticides based on crop type. The app also allows growers to take notes, access scouting reports, set alerts, and share results by email. The app can be downloaded from Genuity.com/RootwormManager or the iTunes® App Store.

XtendiMax® herbicide with VaporGrip® Technology is a restricted use pesticide for retail sale to and use only by Certified Applicators or persons under their direct supervision. ALWAYS READ AND FOLLOW DIRECTIONS FOR USE ON PESTICIDE LABELING. It is a violation of federal and state law to use any pesticide product other than in accordance with its labeling. XtendiMax® herbicide with VaporGrip® Technology may not be approved in all states and may be subject to use restrictions in some states. Check with your local Monsanto dealer or representative or U.S. EPA and your state pesticide regulatory agency for the product registration status and additional restrictions in your state. For approved tank-mix products and nozzles visit XtendiMaxApplicationRequirements.com

Commercialization is dependent on multiple factors, including successful conclusion of the regulatory process. The information presented herein is provided for educational purposes only, and is not and shall not be construed as an offer to sell, or a recommendation to use, any unregistered pesticide for any purpose whatsoever. It is a violation of federal law to promote or offer to sell an unregistered pesticide.

Do not export Genuity® Roundup Ready® Alfalfa seed or crop, including hay or hay products, to China pending import approval. In addition, due to the unique cropping practices do not plant Genuity® Roundup Ready® Alfalfa in Imperial County, California, pending import approvals and until Forage Genetics International, LLC (FGI) grants express permission for such planting.

Forage Genetics International, LLC (“FGI”) is a member of Excellence Through Stewardship® (ETS). FGI products are commercialized in accordance with ETS Product Launch Stewardship Guidance, and in compliance with FGI’s Policy for Commercialization of Biotechnology-Derived Plant Products in Commodity Crops. Certain products have been approved for import into key export markets with functioning regulatory systems. Any crop or material produced from this product can only be exported to, or used, processed or sold in countries where all necessary regulatory approvals have been granted. It is a violation of national and international law to move material containing biotech traits across boundaries into nations where import is not permitted. Growers should talk to their grain handler or product purchaser to confirm their buying position for this product. Growers should refer to http://www.biotradestatus.com/ for any updated information on import country approvals. Excellence Through Stewardship® is a registered trademark of Biotechnology Industry Organization.

Monsanto Company is a member of Excellence Through Stewardship® (ETS). Monsanto products are commercialized in accordance with ETS Product Launch Stewardship Guidance, and in compliance with Monsanto’s Policy for Commercialization of Biotechnology-Derived Plant Products in Commodity Crops. This product has been approved for import into key export markets with functioning regulatory systems. Any crop or material produced from this product can only be exported to, or used, processed or sold in countries where all necessary regulatory approvals have been granted. It is a violation of national and international law to move material containing biotech traits across boundaries into nations where import is not permitted. Growers should talk to their grain handler or product purchaser to confirm their buying position for this product. Excellence Through Stewardship® is a registered trademark of Excellence Through Stewardship.

ALWAYS READ AND FOLLOW DIRECTIONS FOR USE ON PESTICIDE LABELING. IT IS A VIOLATION OF FEDERAL AND STATE LAW to use any pesticide product other than in accordance with its labeling. NOT ALL formulations of dicamba or glyphosate are approved for in-crop use with Roundup Ready 2 Xtend® soybeans. ONLY USE FORMULATIONS THAT ARE SPECIFICALLY LABELED FOR SUCH USES AND APPROVED FOR SUCH USE IN THE STATE OF APPLICATION. Contact the U.S. EPA and your state pesticide regulatory agency with any questions about the approval status of dicamba herbicide products for in-crop use with Roundup Ready 2 Xtend® soybeans.

Roundup Ready 2 Xtend® soybeans contains genes that confer tolerance to glyphosate and dicamba. Glyphosate will kill crops that are not tolerant to glyphosate. Dicamba will kill crops that are not tolerant to dicamba. Glufosinate will kill crops that are not tolerant to glufosinate. Contact your Monsanto dealer or refer to Monsanto’s Technology Use Guide for recommended weed control programs.

B.t. products may not yet be registered in all states. Check with your Monsanto representative for the registration status in your state.

IMPORTANT IRM INFORMATION: RIB Complete® corn blend products do not require the planting of a structured refuge except in the Cotton-Growing Area where corn earworm is a significant pest. SmartStax® RIB Complete® corn blend is not allowed to be sold for planting in the Cotton-Growing Area. See the IRM/Grower Guide for additional information. Always read and follow IRM requirements.

Performance may vary, from location to location and from year to year, as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible and should consider the impacts of these conditions on the grower’s fields.

The Climate FieldView™ services provide estimates or recommendations based on models. These do not guarantee results. Consult your agronomist, commodities broker and other service professionals before making financial, risk management, and farming decisions. Information and recommendations we provide do not modify your rights under insurance policies purchased through our affiliates. More information at www.climate.com/disclaimers.